:root{
  --bg: #0f1220;
  --bg-soft: #14182a;
  --card: rgba(255,255,255,0.06);
  --card-border: rgba(255,255,255,0.12);
  --text: #e9ecf1;
  --text-dim: #b9c2d0;
  --primary: #6ea8fe;
  --primary-strong: #4d90fe;
  --success: #00d1b2;
  --danger: #ff6b6b;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --glass: blur(8px);
}

/* Light theme */
:root.light{
  --bg: #f6f8fc;
  --bg-soft: #ffffff;
  --card: rgba(0,0,0,0.03);
  --card-border: rgba(0,0,0,0.08);
  --text: #111827;
  --text-dim: #4b5563;
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --shadow: 0 8px 24px rgba(0,0,0,0.1);
}

*{ box-sizing: border-box; }

html, body{
  height: 100%;
}

body{
  margin: 0;
  background: radial-gradient(1200px 600px at 10% -10%, #22294b 0%, transparent 55%), 
              radial-gradient(1000px 500px at 110% 10%, #1b264a 0%, transparent 60%),
              var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, "Helvetica Neue", Arial, "Noto Color Emoji", "Apple Color Emoji", "Segoe UI Emoji";
}

.app{
  min-height: 100dvh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.app-header{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px clamp(16px, 4vw, 32px);
  backdrop-filter: var(--glass);
  background: linear-gradient(180deg, rgba(0,0,0,0.18), rgba(0,0,0,0)) , var(--bg-soft);
  border-bottom: 1px solid var(--card-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand{
  display: flex;
  align-items: center;
  gap: 12px;
}
.logo{
  width: 42px; height: 42px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--primary), #9dd1ff);
  border-radius: 12px;
  color: white;
  box-shadow: var(--shadow);
}
h1{
  margin: 0;
  font-size: 1.25rem;
  letter-spacing: 0.2px;
}
.subtitle{
  margin: 0;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.controls{
  display: flex;
  align-items: end;
  gap: 12px;
}
.field{
  display: grid;
  gap: 6px;
  color: var(--text-dim);
  font-size: 0.9rem;
}
.field input{
  background: var(--card);
  border: 1px solid var(--card-border);
  color: var(--text);
  padding: 10px 12px;
  border-radius: 10px;
  outline: none;
  min-width: 220px;
}
.field input:focus{
  border-color: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in lab, var(--primary) 20%, transparent);
}

.chat-layout{
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 16px;
  padding: 16px clamp(16px, 4vw, 32px);
}

.sidebar{
  display: grid;
  gap: 16px;
  height: calc(100% - 12px);
}

.panel{
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 14px;
  box-shadow: var(--shadow);
}
.panel h3{
  margin: 0 0 10px 0;
  font-size: 1rem;
  color: var(--text-dim);
}
.room-list{
  list-style: none;
  padding: 0;
  margin: 0;
}
.room{
  padding: 10px 12px;
  border-radius: 10px;
  color: var(--text);
  cursor: pointer;
}
.room:hover{
  background: color-mix(in lab, var(--primary) 18%, transparent);
}
.room.active{
  background: color-mix(in lab, var(--primary) 28%, transparent);
  border: 1px solid color-mix(in lab, var(--primary) 55%, var(--card-border));
}

.status{
  font-size: 0.9rem;
  color: var(--text-dim);
}

.chat{
  display: grid;
  grid-template-rows: 1fr auto;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow);
  min-height: 60dvh;
}

.messages{
  padding: 16px;
  overflow: auto;
  display: grid;
  align-content: start;
  gap: 10px;
  background:
    radial-gradient(800px 300px at 60% -10%, rgba(255,255,255,0.08), transparent 60%),
    radial-gradient(800px 300px at 20% -10%, rgba(255,255,255,0.05), transparent 60%),
    transparent;
}

.message{
  display: grid;
  gap: 4px;
  max-width: 80%;
  padding: 10px 12px;
  border-radius: 12px;
  background: rgba(255,255,255,0.08);
  border: 1px solid var(--card-border);
  box-shadow: 0 6px 20px rgba(0,0,0,0.18);
}
.message.me{
  margin-left: auto;
  background: color-mix(in lab, var(--primary) 35%, rgba(255,255,255,0.08));
  border-color: color-mix(in lab, var(--primary) 65%, var(--card-border));
}
.message .meta{
  display: flex;
  gap: 8px;
  font-size: 0.75rem;
  color: var(--text-dim);
}
.message .text{
  white-space: pre-wrap;
  word-wrap: break-word;
}

.composer{
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  border-top: 1px solid var(--card-border);
  padding: 12px;
  background: linear-gradient(180deg, rgba(0,0,0,0), rgba(0,0,0,0.12));
}
.composer input{
  background: rgba(255,255,255,0.08);
  border: 1px solid var(--card-border);
  color: var(--text);
  padding: 12px 14px;
  border-radius: 12px;
  outline: none;
}
.composer input:focus{
  border-color: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in lab, var(--primary) 20%, transparent);
}

.btn{
  appearance: none;
  border: 1px solid transparent;
  padding: 10px 14px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 600;
  box-shadow: var(--shadow);
}
.btn.primary{
  background: linear-gradient(180deg, var(--primary), var(--primary-strong));
  color: #fff;
}
.btn.secondary{
  background: var(--card);
  color: var(--text);
  border-color: var(--card-border);
}

.app-footer{
  padding: 10px clamp(16px, 4vw, 32px);
  color: var(--text-dim);
  text-align: center;
}

/* Mobile */
@media (max-width: 880px){
  .chat-layout{
    grid-template-columns: 1fr;
  }
  .sidebar{
    order: 2;
  }
}